Vehicle frames often have their opposite end portions bent upwardly or downwardly as a result of accident involving front or rear end damage. In order to straighten such a distorted vehicle frame, it is advantageous to establish a datum line adjacent the frame in order that the distance of certain frame portions from the datum line may be checked and corrected (by frame bending) when necessary.
If a bent vehicle frame is not restored to its proper dimensions and spacial relationships relative to a datum line, interference between adjacent body components may result and the various running gear components of the vehicle may not be properly positioned relative to the frame in order to assure proper riding and handling characteristics.
Although datum line charts for various motor vehicle frames are provided by the corresponding motor vehicle manufacturers and similar charts may be reasonably accurately produced for other models of motor vehicles whose manufacturers do not provide datum line charts, present methods of establishing datum lines relative to a vehicle frame are cumbersome and time consuming. Accordingly, a need exists for quickly and accurately establishing a vehicle frame datum line.
Various frame gauge structures and assemblies, including some of the general structural and operational features of the instant invention, are disclosed in U.S. Pat. Nos. 2,798,296, 3,057,074, 3,151,396 and 3,661,575. However, these previously known structures involve the expenditure of considerable time to achieve proper positioning thereof relative to an associated vehicle frame and are not readily usable in conjunction with all types of frames and unitized vehicle body structures, including sub-frames.